This article was taken from the January 2013 issue of Wired magazine. Be the first to read Wired's articles in print before they're posted online, and get your hands on loads of additional content by <span class="s1">subscribing online.
Kenny Salvini hit the slopes with his friends one night in February 2004 and scored major air off a terrain park ramp. Only trouble was, he then plummeted from the height of a three-storey house and landed on his back. It's easy to blame youthful daring and bad luck, but it turns out that the raw physics of the ramp were also against him.
Paralysed from the shoulders down, Salvini was awarded $14 million (£8.7 million) in damages when engineers' testimony showed that his injuries partly resulted from the jump's design.
Most terrain parks don't stick to mathematical standards, but physicist Jim McNeil thinks better specs could prevent accidents. He suggests a simple metric to reduce risk: equivalent fall height (EFH), which expresses the shock a jumper absorbs in terms of an equivalent vertical drop on to a flat surface. A well-designed ramp can launch you to a height of around 10m, yet have an EFH of just two.
Not everyone buys it. The equations governing EFH "assume that the human is like a cannon ball", argues sports-injury researcher Jake Shealy, who worries that it doesn't allow for variables such as rider skill and snow texture. McNeil counters that the formula can suggest designs to minimise risk. He's also built a device to analyse jumps. Since you don't have one, though, be sure to look before you leap. And land feet-first.
This article was originally published by WIRED UK
